[PATCH v6 00/21] Add gdb python scripts as kernel debugging helpers

[PATCH v6 00/21] Add gdb python scripts as kernel debugging helpers

[Jan Kiszka]

It's been a while since my last update of these patches. This one is
mostly about cleaning up and making some details more convenient:
 - proper registration of module data segments to access module
   variables - this obsoletes lx_modvar again
 - stable breakpoint target on do_init_module in order to track module
   loading more reliably from the debugger
 - internal refactoring with the aim to "pythonize" the scripts (credits
   for all valuable suggestions belong to Tatiana, many thanks, for
   improper implementations to me)

See http://lkml.indiana.edu/hypermail/linux/kernel/1210.0/01598.html for
the original description and

    git://git.kiszka.org/linux.git queues/gdb-scripts

for the latest version.

Jan

CC: "David S. Miller" <davem@davemloft.net>
CC: Fenghua Yu <fenghua.yu@intel.com>
CC: Kay Sievers <kay@vrfy.org>
CC: linux-doc@vger.kernel.org
CC: linux-ia64@vger.kernel.org
CC: linux-kbuild@vger.kernel.org
CC: Michal Marek <mmarek@suse.cz>
CC: Rob Landley <rob@landley.net>
CC: sparclinux@vger.kernel.org
CC: Tony Luck <tony.luck@intel.com>

Jan Kiszka (21):
  scripts/gdb: Add infrastructure
  scripts/gdb: Add cache for type objects
  scripts/gdb: Add container_of helper and convenience function
  scripts/gdb: Add module iteration class
  scripts/gdb: Add lx-symbols command
  module: Do not inline do_init_module
  scripts/gdb: Add automatic symbol reloading on module insertion
  scripts/gdb: Add internal helper and convenience function to look up a
    module
  scripts/gdb: Add get_target_endianness helper
  scripts/gdb: Add read_u16/32/64 helpers
  scripts/gdb: Add lx-dmesg command
  scripts/gdb: Add task iteration class
  scripts/gdb: Add helper and convenience function to look up tasks
  scripts/gdb: Add is_target_arch helper
  scripts/gdb: Add internal helper and convenience function to retrieve
    thread_info
  scripts/gdb: Add get_gdbserver_type helper
  scripts/gdb: Add internal helper and convenience function for per-cpu
    lookup
  scripts/gdb: Add lx_current convenience function
  scripts/gdb: Add class to iterate over CPU masks
  scripts/gdb: Add lx-lsmod command
  scripts/gdb: Add basic documentation

 Documentation/gdb-kernel-debugging.txt | 159 +++++++++++++++++++++++++++++++
 Makefile                               |   5 +-
 kernel/module.c                        |   9 +-
 scripts/Makefile                       |   3 +-
 scripts/gdb/Makefile                   |  11 +++
 scripts/gdb/linux/Makefile             |   9 ++
 scripts/gdb/linux/__init__.py          |   0
 scripts/gdb/linux/cpus.py              | 139 +++++++++++++++++++++++++++
 scripts/gdb/linux/dmesg.py             |  64 +++++++++++++
 scripts/gdb/linux/modules.py           | 111 ++++++++++++++++++++++
 scripts/gdb/linux/symbols.py           | 166 +++++++++++++++++++++++++++++++++
 scripts/gdb/linux/tasks.py             | 108 +++++++++++++++++++++
 scripts/gdb/linux/utils.py             | 156 +++++++++++++++++++++++++++++++
 scripts/gdb/vmlinux-gdb.py             |  30 ++++++
 14 files changed, 966 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/gdb-kernel-debugging.txt
 create mode 100644 scripts/gdb/Makefile
 create mode 100644 scripts/gdb/linux/Makefile
 create mode 100644 scripts/gdb/linux/__init__.py
 create mode 100644 scripts/gdb/linux/cpus.py
 create mode 100644 scripts/gdb/linux/dmesg.py
 create mode 100644 scripts/gdb/linux/modules.py
 create mode 100644 scripts/gdb/linux/symbols.py
 create mode 100644 scripts/gdb/linux/tasks.py
 create mode 100644 scripts/gdb/linux/utils.py
 create mode 100644 scripts/gdb/vmlinux-gdb.py

-- 
1.8.1.1.298.ge7eed54

[PATCH v6 15/21] scripts/gdb: Add internal helper and convenience function to retrieve thread_info

[Jan Kiszka]

Add the internal helper get_thread_info that calculates the thread_info
from a given task variable. Also export this service as a convenience
function.

Note: ia64 version is untested.

CC: Tony Luck <tony.luck@intel.com>
CC: Fenghua Yu <fenghua.yu@intel.com>
CC: linux-ia64@vger.kernel.org
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 scripts/gdb/linux/tasks.py | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/scripts/gdb/linux/tasks.py b/scripts/gdb/linux/tasks.py
index 13bb97c..63cd6c5 100644
--- a/scripts/gdb/linux/tasks.py
+++ b/scripts/gdb/linux/tasks.py
@@ -71,3 +71,38 @@ return that task_struct variable which PID matches."""
 
 
 LxTaskByPidFunc()
+
+
+thread_info_type = utils.CachedType("struct thread_info")
+
+ia64_task_size = None
+
+
+def get_thread_info(task):
+    global thread_info_type
+    thread_info_ptr_type = thread_info_type.get_type().pointer()
+    if utils.is_target_arch("ia64"):
+        global ia64_task_size
+        if ia64_task_size is None:
+            ia64_task_size = gdb.parse_and_eval("sizeof(struct task_struct)")
+        thread_info_addr = task.address + ia64_task_size
+        thread_info = thread_info_addr.cast(thread_info_ptr_type)
+    else:
+        thread_info = task['stack'].cast(thread_info_ptr_type)
+    return thread_info.dereference()
+
+
+class LxThreadInfoFunc (gdb.Function):
+    """Calculate Linux thread_info from task variable.
+
+$lx_thread_info(TASK): Given TASK, return the corresponding thread_info
+variable."""
+
+    def __init__(self):
+        super(LxThreadInfoFunc, self).__init__("lx_thread_info")
+
+    def invoke(self, task):
+        return get_thread_info(task)
+
+
+LxThreadInfoFunc()
-- 
1.8.1.1.298.ge7eed54